diff --git a/Project.toml b/Project.toml
index c4182cfd..a495df86 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "FillArrays"
 uuid = "1a297f60-69ca-5386-bcde-b61e274b549b"
-version = "1.3.0"
+version = "1.4.0"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
diff --git a/src/FillArrays.jl b/src/FillArrays.jl
index 3222a8f7..4b2dbe47 100644
--- a/src/FillArrays.jl
+++ b/src/FillArrays.jl
@@ -6,7 +6,8 @@ import Base: size, getindex, setindex!, IndexStyle, checkbounds, convert,
     +, -, *, /, \, diff, sum, cumsum, maximum, minimum, sort, sort!,
     any, all, axes, isone, iterate, unique, allunique, permutedims, inv,
     copy, vec, setindex!, count, ==, reshape, _throw_dmrs, map, zero,
-    show, view, in, mapreduce, one, reverse, promote_op, promote_rule, repeat
+    show, view, in, mapreduce, one, reverse, promote_op, promote_rule, repeat,
+    parent
 
 import LinearAlgebra: rank, svdvals!, tril, triu, tril!, triu!, diag, transpose, adjoint, fill!,
     dot, norm2, norm1, normInf, normMinusInf, normp, lmul!, rmul!, diagzero, AdjointAbsVec, TransposeAbsVec,
@@ -369,6 +370,8 @@ axes(T::UpperOrLowerTriangular{<:Any,<:AbstractFill}) = axes(parent(T))
 axes(rd::RectDiagonal) = rd.axes
 size(rd::RectDiagonal) = map(length, rd.axes)
 
+parent(rd::RectDiagonal) = rd.diag
+
 @inline function getindex(rd::RectDiagonal{T}, i::Integer, j::Integer) where T
     @boundscheck checkbounds(rd, i, j)
     if i == j
@@ -411,7 +414,8 @@ Base.replace_in_print_matrix(A::RectDiagonal, i::Integer, j::Integer, s::Abstrac
 
 
 const RectOrDiagonal{T,V,Axes} = Union{RectDiagonal{T,V,Axes}, Diagonal{T,V}}
-const RectDiagonalEye{T} = RectDiagonal{T,<:Ones{T,1}}
+const RectOrDiagonalFill{T,V<:AbstractFillVector{T},Axes} = RectOrDiagonal{T,V,Axes}
+const RectDiagonalFill{T,V<:AbstractFillVector{T}} = RectDiagonal{T,V}
 const SquareEye{T,Axes} = Diagonal{T,Ones{T,1,Tuple{Axes}}}
 const Eye{T,Axes} = RectOrDiagonal{T,Ones{T,1,Tuple{Axes}}}
 
@@ -537,6 +541,15 @@ convert(::Type{AbstractSparseArray{Tv,Ti}}, Z::Eye{T}) where {T,Tv,Ti} =
 convert(::Type{AbstractSparseArray{Tv,Ti,2}}, Z::Eye{T}) where {T,Tv,Ti} =
     convert(SparseMatrixCSC{Tv,Ti}, Z)
 
+function SparseMatrixCSC{Tv}(R::RectOrDiagonalFill) where {Tv}
+    SparseMatrixCSC{Tv,eltype(axes(R,1))}(R)
+end
+function SparseMatrixCSC{Tv,Ti}(R::RectOrDiagonalFill) where {Tv,Ti}
+    Base.require_one_based_indexing(R)
+    v = parent(R)
+    J = getindex_value(v)*I
+    SparseMatrixCSC{Tv,Ti}(J, size(R))
+end
 
 #########
 # maximum/minimum
diff --git a/src/fillalgebra.jl b/src/fillalgebra.jl
index 6d5c8394..2d1d5eca 100644
--- a/src/fillalgebra.jl
+++ b/src/fillalgebra.jl
@@ -453,4 +453,4 @@ function kron(f::AbstractFillVecOrMat, g::AbstractFillVecOrMat)
     sz = _kronsize(f, g)
     _kron(f, g, sz)
 end
-kron(E1::RectDiagonalEye, E2::RectDiagonalEye) = kron(sparse(E1), sparse(E2))
+kron(E1::RectDiagonalFill, E2::RectDiagonalFill) = kron(sparse(E1), sparse(E2))
diff --git a/test/runtests.jl b/test/runtests.jl
index 1ffd2d5a..546be82a 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -514,6 +514,28 @@ end
                 convert(AbstractSparseMatrix{Float64,Int},Mat) ==
                 SMat
     end
+
+    function testsparsediag(E)
+        S = @inferred SparseMatrixCSC(E)
+        @test S == E
+        S = @inferred SparseMatrixCSC{Float64}(E)
+        @test S == E
+        @test S isa SparseMatrixCSC{Float64}
+        @test convert(SparseMatrixCSC{Float64}, E) == S
+        S = @inferred SparseMatrixCSC{Float64,Int32}(E)
+        @test S == E
+        @test S isa SparseMatrixCSC{Float64,Int32}
+        @test convert(SparseMatrixCSC{Float64,Int32}, E) == S
+    end
+
+    for f in (Fill(Int8(4),3), Ones{Int8}(3), Zeros{Int8}(3))
+        E = Diagonal(f)
+        testsparsediag(E)
+        for sz in ((3,6), (6,3), (3,3))
+            E = RectDiagonal(f, sz)
+            testsparsediag(E)
+        end
+    end
 end
 
 @testset "==" begin
@@ -1534,6 +1556,12 @@ end
     C = collect(E)
     @test K == kron(C, C)
     @test issparse(kron(E,E))
+
+    E = RectDiagonal(Fill(4,3), (6,3))
+    C = collect(E)
+    K = kron(E, E)
+    @test K == kron(C, C)
+    @test issparse(K)
 end
 
 @testset "dot products" begin